A pool remodel is one of the few home projects where timing genuinely matters. Plaster cures best in moderate temperatures, you can't swim while the pool is empty, and in North Texas the calendar between October and March is when all three of those line up. If you can plan a remodel for the off-season, you'll get better scheduling, better curing conditions, and a pool that's ready before the first hot weekend in May.
Order of work matters just as much. The pool gets drained once, so anything that needs an empty pool should happen in the same window: skimmer and main drain replacement first, then tile and coping, then any stone or water feature work, and plaster last, since it's the finish surface and shouldn't be walked on or worked around once it's applied. A good estimate lays this sequence out with a day count so you know how long the pool will be down.
Expect a replaster-only job to run about one to two weeks from drain to refill, longer if tile and coping are included, and longer still for demolition, stone, or plumbing changes. Weather can move the schedule; rain and freezing temperatures both stop plaster work. Ask for a written scope that lists what happens if something is found once the pool is empty, because on a 20-year-old pool, something usually is.
Finally, the questions worth asking any contractor: Who actually does the work, your crew or subcontractors? Is the estimate itemized, with materials and labor separated? What's the warranty on plaster, tile, and coping? And will the final invoice wait until the pool is full and you've walked it together? Those four answers tell you most of what you need to know.